Electromagnetic circuit



Nov. 23,1948. 7 G. D. CRAIG@ '2,454,634

Find Aug. 9.

4 Sheets-Sheet 3 IN V EN TOR.

Patented Nov. V23, 1948 UNITED sTATEs PATENT orales 2,454,634 ELECTROMAGNETIC CIRCUITkr George D. Craig, II, Flushing, 4N. Y. Application August 9, 1945, Serial No. 609,893

l y 6 Claims. l

This application for patent describes my invention relating to electro-magnetic circuits. The invention is illustrated as applied in one embodiment to the operation of a planing device but it is to be specifically understood that this is merely an illustration oi one use oi' my improved electro-magnetic circuit.

For many purposes and in many operations, it is desirable to have available and to utilize electrical currents, the characteristics of which vary lo according to a regular, recurring, pattern with the passage of time. Thus, the voltage-time characteristic, the current-time characteristic, or the phase-time characteristic, or any combination thereof, may desirably be caused to follow l5 a deilnite pattern, which pattern is repeated over and over again during the operation of the device. When the operation ci' the device is to be changed, or when the current supplying circuit is to be used with a different device, it is often desirable to change the recurring pattern to adapt it to the changed operation or the diierent mechanism.

The present invention is directed to the provision of means to generate or control an electric current or currents, so as to provide an electric current or currents, the characteristics oi which follow a predetermined, recurring, time pattern, and which predetermined, recurring, time pattern can be readily changed or adjusted.

The output of an electromagnetic circuit con-` structed in accordance with this invention is ans, electrical current, one or more characteristics of which vary in accordance with time and inaccordance with a recurring pattern. The electromagnetic circuit of this invention is sc arranged that it can be expediently adjusted to change the pattern so that a current of the desired pattern of characteristics can be supplied for any one oi the great number of purposes.

For example, in operating machine tools, such as planers and shapers, it is often desirable/'tof have the machine travel relatively slowly during the cutting stroke and then travel relatively rapidly during the return stroke. Well known means are available for controlling the speed o! such a device in accordance with the voltage oi' a current supplied to a control device, and by means of the 'present invention a current can be supplied to the control device, the voltage of which will vary in accordance with' time, Just as it is desired to vary the speed of operation of the planer cr Shaper. Thus, by the use of the present invention, the operation of a planer or shaper may be expediently controlled to cause it to operate slowly during the cutting stroke and rapidly during the return stroke.

To anyone-versed in the electro-mechanical art, many constructional schemes will become obvious for obtaining the objectives of this invention. Therefore, it is to be expressly understood that my idea is not limited by physical construction inasmuch as the objectives outlinedin this application may be obtained with a device or devices assuming many combinations oi' the structural features oi generators (including permanent magnet type), motors, selisynchronous devices, toroidal wound devices, variable transformera, etc., wherein a single unit consists lof at least two elements such as a stator and a rotor, where said rotor and stator elements may have a single phase winding or a plurality oi phases Y and poles, where said stator and rotor of each single unit may have either` or both elements constructed with a single phase winding or a plurality of phases and poles,'where either of said elements is capable of being positioned orrotated with respect to the other and where one or more coils oi any element may be energized from an electrical source, said source being direct current. single or multi-phase pulsatingl or alternating current.

The figures oi' this application show elementary schematic electrical and mechanical connections of two or more devices which when properly manipulated give one or more voltage changes definitely related to one another and each following a mathematical transcendental function.

One of the objects or my invention is, therefore, the production of electrical currents having characteristics which vary in accordance with a recurring pattern with respect to time, which pattern can be controlled as desired.

' A further ylcbject of the invention is a method of 0 producing arid controlling electrical currents so as to give them characteristics which follow a deilnite recurring pattern with respect to time and utilizing such electrical currents for the operation and/or controlling of operations in any desired field. 1

A further object ci the invention is the provision of means and/or machines for producing andy controlling electrical currents hajoging designatd characteristics.

Cine of the features oi my invention is the provision of a transformer apparatus through which an alternating current (or if desired a direct current) may induce a current having a characteristic which may be controlled to take any shape.

sa, ci?

Further objects and features of my invention will be apparent Ctrom a reading oi' the subioined specification and claimt in connection with the accompanying drawings illustrating several spe-s cie-,embodiments of my invention.

In the drawings:

Figure 1 is a diagrammatic view illustrating one embodiment of my invention as applied to the operation of a planing device;

--Figure 2 is a diagrammatic illustration of another embodiment; of -my invention, in which the induced currents are 120 apart;

Figure 3V is a diagrammatic illustration of a third embodiment of my invention which is similar to that of Figure 2, except that the two rotors illustrated are geared to rotate at a rate proportional-,one to the other;

lFigure 4 1s a diagrammatic view of anotheremelements, and in which the current of each .of the rotor elements and of'each of the stator elements is two phase;

Figure 5 is a graph disclosing the resulting or output voltage curves of the currents induced in the stator elements by the circuit illustrated in Figure 2;

Figure 6 is a straight line graph showing the resulting voltages induced in the stator circuit by the arrangement disclosed in Figure 2, and

Figure 7 is a graph illustrating the resulting voltages induced in the stator circuit by the ar rangement shown in Figure 3.

Referring specifically to the drawings, it may be seen that I have illustrated in Figure l. an arrangement in which alternating current is supplied from a suitable source through inlet leads iI and I2 connected to winding i3 of rotor element I4 and to winding i5 of rotor element I6. Associated with rotor element i4 is a stator element illustrated by coil il and associated with' rotor element I6 is a stator element illustrated by coil I8. The current induced inthe circuit I9 which includes the stator elements Il and I8 controls the operation of a motor control 2|, which controls the speed at which an electric motor 24 is operated, in accordance with the voltage or current in the circuit I9. The motor control 2| may comprise any of the usual con- .trol elements, such as Selsyn motors, thyratron tubes and the like. These are all well known and are not described in detail here. The motor 24 is arranged to drive a belt 25 and a pinion 26, which in turn operates the movable element 2'I of a planer 28. The voltages induced in the circuit I9 are controlled by the position of the rotors I4 and I6 so that when the movable element 21 ismoving forward in its operating stroke it moves at a relatively slow speed so that the shaving or planing operation may be eilclently accomplished. However, when it is moving on its return stroke the voltages induced are such that the motor 24 is operated at a higher rate oi' speed and the movable element 2'I is returned at a relatively high speed.

The control of the voltages induced in the circuit I9 is accomplished in the following manner: The current supplied through the wires II and I2 to the windings I3 and I5 is alternating current and thus creates in the coils I1 and I8 an alternating current induced thereby. If the rotors I3 and I5 were properly positioned angularly and held stationary, the phases of the induced currents synchronized, the current induced in the two windings I`I and I8 would be substantially the same. iammy device the rotor I8 is held stationary while the rotor I4 is rotated relative to the stator coil il.. Thus, at times the current induced inthe coil Il is in phase with -the current induced. in the coil I8, while at other times the currents induced in said coils `conflict with eachother andthus .decrease the voltages induced.- Thus, li may by rotating the rotor ,It at proper speeds, cause the induced current .tg assume a voltage characteristic such that it controls the flow of current to operate the motor 2t during the shaving stroke at the desired .bodiment of my invention in which there are provided three rotor elements and three stator speed and on the returdstroke operates it at a dlierentmelatively switer speed. The rotor It may be rotated by any conventional means such, for example, as a small electric motor connected to the rotor through suitable gearing. The other rotor I6 may be held stationary, and its position adjusted manually'from time to time to adjust the pattern of the current output of the control device or may, as indicated in some of the following examples, be rotated by an independent source oi' power, or by beingV geared ,to the firstmentioned rotor I4. Since numerous well known means are available for rotating either or both of the rotors, It is not desired to limit the present application to the use of any specic means ior rotating or holding stationary, or adjusting the position of, either of the rotors.

I will now refer to Figures 2,' 5 and 7 for a more detailed description of the possibilities oi controlling the Induced currents.- A

Figure 2 shows two units electrically connected so that three output voltages VI, Y2 and V3 apart) vary in magnitude and phase when rotor #I is positioned and held stationary -whilc rotor #2 is positioned or made to turn at-'any given rate. The results of V2 from this action may be found plotted on the graphs ol' Figures. 5 and 6. VI and V3 would, of course, be positioned 120 either side of Vt. It may be seen that in Figure 2 I have provided a rotor 3| 4and a rotor 32. these rotors having windings 33 and 3'4 respectively which are connected in electrical circults 4I and 42 to which alternating current is supplied by leads 43 and 44. These rotors 3| and 32 are single phase, salient pole rotors. The alternating current supplied through leads 43 and 44 causes electrical currents to be generated in the stator windings. The rotor 3| is intended to remain normally stationary but may be set at any desired angle relative to the stator element. The rotor 32 on the other hand is lntended to be rotated continuously during operation so as to produce the desired voltage wave throughout its operation.

The stator elements associated with the rotor elements 3| and 32 are designated 45 and 48, respectively. Each stator is three phase and two pole and they each have three windings designated 41, 48 and 49 and 5I, 52 and 53. Windings 41 and 51 are connected in series as are windings 48 and 52. and windings 43 and 53. Each of these pair of windings is spaced 120 on the stator element so that if the rotor elements 3| and 32 were positioned so as to generate electric voltages in the stator elements in phase, the voltages induced in 41, 48 and 49 would each reinforce or build up the voltages induced in 5I, 52 and 63, respectively. Inasmuch, however, as rotor 3| is maintained stationary while rotor 32 is rotated, the voltages induced will vary, depending upon the setting of rotor 3| and upon the speed of roiation of rotor 32. For instance, with settings of rotor 3| at 30. 45, 60, 75 and 90, the voltages induced in each of the sets of windings of the stator elements 45 and 46 will follow the curves disclosed in Figure 5, the equations for which are and sin onstraight line coordinates in Figure 6, wherein 1 the curves designated as 0, 30, 45, 60. and 90, each represent the voltage induced when the rotor 3| is set with an angle of 0, 30, 45, 60, '15 and 90, respectively.

In Figure 3, I have shown another embodiment of my invention. Figure 3 is identical to Figure 2, except that rotors #1' and #2 are mechanically connected to one another (e. g. geared together). Results of V2 for this set-up may be found plotted on the graph shown in Figure '1. It is to be noted that the resulting transcendental function is dependent upon the gearing ratio or the relative angular movement of one or more rotors with respect to another rotor or rotors wherein the rotors are elements of separate units or devices consisting of two elements as heretofore explained.

In the specific arrangement illustrated in Figure 3, the rotors |3| and |32 are so geared to each other so that rotor |32 is rotated at a speed of rotation that is twice the speed of rotation of unit |3|. Stator elements |45 and |46 correspond substantially to stator elements 45 and 46, the combined voltages induced being led by means of connections |54, |55 andv |56 to devices which it is desired to operate by means of the induced currents. l

The currents and voltages which are induced in the circuits |54, |55 and |56 are each similar `to each other, but are spaced at intervals of 120 each. Their characteristics are shown in the curves of output voltage V2 of Figure '1, using the circuit of Figure #3 and using a gear ratio between the two rotor elements of 2 to l. It is to be understood that any desired gear ratio may be used or any desired mechanical connection between the two rotors |3| and |32 may be pro"- vided so that any desired relation of movement between the two rotors may be accomplished, and thus any desired characteristics of the output voltages may be secured.

In Figure 4 I have disclosed still another embodiment of my invention. This ligure shows an extension of the basic idea wherein there are three units with electrical connections similar to those in Figures 2 and 3 but with non-salient pole rotors wound multi-phase and energizedv from a multi-phase source. In this embodiment two phase alternating current is supplied through leads |6|, |62 and |63 to rotor elements |64, .|65

and |66. Each of these rotor elements includes-- two coils, such as |64a and |64b, |65a and |6517 and' |66 a and |66b and similarly, the stator elements |61, |68 and |69 each have two coils such as |61a and |6112, |68a and |68b and |6841 and |69b. The induced voltages of the stator elements |61, |68 and |69 are thus controlled (a) by the fact that the rotor elements |64, |65 and |66 have two phase windings (b) by the fact that the stator elements |61, |68 and |68 have two phase windings (c) by the setting of rotor element |64 (d) by the setting of rotor element |65 and (e) by the setting of rotor element |66. These induced voltages for phase are led of! to the work to be performed'by a circuit including leads tionen', while the rotor It is to be understood that while I have disl closed my invention as designed to use alternating current, it is possible also in certain cases to use direct current. For example, referring to Figure 1, wherein the rotor I5 is maintained sta- |3 is rotated, it may -be seen that with the use of direct current in rotor I3, an alternating current` would be induced in the stator 'element |1 which would pass through the stator coil uence of the eld of stationary rotor |5 having direct current supply thereto would modify the characteristics of the voltages induced in the circuit including the coils |1 and |8 arranged in series.

Thus it is to be seen by anyone versed in the electrical art that an infinite number of voltage patterns m-ay be obtained with two or more units mechanically and electrically connected as shown in Figures 1, 2, 3 and 4, and their rota-table elements manipulated by data sources. I,

The scope of this invention may be appreciated from the following examples of diversiiled objectives:

1. The formation of voltage output patterns following, e. gf, the polar equation sin2 2.'To provide a variable voltage source having a. variable phase relation with respect to the pri# mary or energizing voltage source wherein the phasing angle is a function of unit rotor angle.

3. To provide a means of varying the phasel angle and magnitude of the induced (output) voltage from 0 to 360 or more.

4. To provide a means for transforming uniform mechanical motion into variable motion through utilization of circuits such as those shown in Figures 1, 2, 3 and 4 in a manner analogous to mechanical cam operation.

5. To provide means for converting mechanical motion into an infinite numberof electrical or mechanical quantities each following a definite transcendental function and then repeating said pattern after desired intervals of time.

6. To provide a means for translating mechanical data into electrical data, the latter bearing definite relationship to transcendental functions.

'7. To provide a means for conveying and converting data remotely into an infinite number of desired transcendental functions.

8. To provide an adjustable timing source through the interim of adjustable voltage phasing and/or magnitude.

9. To provide a means of introducing corrective measures in an electrical or mechanical device.

10. To provide means for solving given transcendental functions involving elapsed time, voltage magnitude and angular motion.

11. To provide a meansfor producing mechanical power output with variable speed, controlled through loading of induced voltage windings.

12. To provide means for producing mechani- |1|, and |12, and those induced by the othemhase 'l5 cal power output wunsch-synchronizing action I8 and thus coming under the inof two or more rotatable elements through loading of induced voltage windings.

These various objectives present a general picture of the numerous applications and innovations of this invention and in view of its capacity said aims and objectives set forth are not to be construed as limiting the scope of the basic idea.

It is to be understood that the above described embodiments of my invention are for the purpose of illustration only and various changes may be made therein without departing from the spirit and scope of the invention.

I claim:

1. A device for producing an electrical current, the characteristics of which vary in accordance with the passage of time in a fixed recurring, non' sinusoidal pattern that comprises at least two inductances connected in series, means for producing an electromagnetic eld, means for producing relative cyclical movement between said eld and one of said inductances so that said inductance is cyclically acted upon by s-aid ileld and means for producing a second electromagnetic eld independent of the rst and applying said second electromagnetic field to another of said inductances.

2. A device as dened in claim l further characterized in that means are also prqvided for relatively moving said second electromagnetic iield and the inductance upon which it acts.

3. A device as dened in claim 1 further characterized in' that means are provided for relatively moving in a cyclic manner, said second electromagnetic field and the inductance upon which itacts.

8 4. A device as defined in claim 1 further chai'- acterized in that means are provided for adjusting the relative positions of said second electromagnetic eld and the inductance upon which it acts. V

5. A device as defined in claim 1 further char- `acterized in that means are provided to produce relative movement between said second electromagnetic ileld'and the inductance upon which it acts in a predetermined relation to the relative movement between said first electromagnetic field and the inductance upon which it acts.

6. A device as dened in claim 1 further characterized in that means are provided for producing relative cyclic movement between said second electromagnetic field and the inductance upon which it acts, and in which the means for producing the relative movement between the first field and inductance and the means for producing the relative movement between the second eld and inductance are geared together so that the two movements bear` a constant relationship.

GEORGE D. CRAIG, n.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,768,953 Hellmund July 1, 1930 2,287,603 Clymer June 23, 1942 2,398,390 Ogurkowski Apr. 16, 1946 

